Joint optimisation of double warning T2-Hotelling chart and maintenance policy with multiple assignable causes

Statistical process monitoring (SPM) and maintenance management as two key tools for process management can create profound economic benefits, particularly when they are coordinated. This paper demonstrates the value of integrating SPM and maintenance by presenting a multi-objective model consisting of both economic and statistical criteria. Furthermore, to more adapt to complex manufacturing systems, the proposed model consists of two features: (1) monitoring several correlated quality characteristics by designing a double warning lines 'T-2-Hotelling' chart; and (2) considering the probability of occurrence for more than one assignable cause (AC). To show the effectiveness of the proposed integrated model, two comparative studies are conducted. The first one confirms that the integration of SPM and maintenance policy leads to more effective performance in both economic and statistical viewpoints. The latter results demonstrate that the proposed model outperforms the corresponding single objective models.